(It\'s probably a dumb question due to my limited knowledge with Docker or mysql administration, but since I spent a whole evening on this issue, I dare to ask it.)
run following command to run container
docker run --name db_name -e MYSQL_ROOT_PASSWORD=PASS--publish 8306:3306 db_name
run this command to get mysql db in host machine
mysql -h 127.0.0.1 -P 8306 -uroot -pPASS
in your case it is
mysql -h 127.0.0.1 -P 12345 -uroot -pPASS